The evolution of cats?
As far as I’m concerned, Life, the Universe, and Everything appeared just so this young lion could get that much satisfaction from a green rubber ball. You’re welcome, Leo.
We’re done here . . .
Wait. Why pass up such a fascinating topic?
It may take a PhD to cover every detail of where cats come from and where they might be going, but some of the most interesting highlights aren’t at all hard to understand.
Let’s check out ten common misconceptions about fossil cats and how they turned into the modern cat family Felidae.
To start off, most people think that . . .
10. Dogs and cats are unrelated.
Cats and dogs work hard to keep this misconception going, but they’re actually “kissing cousins.” Well, sort of.
Not much hard evidence of the carnivoran family tree has survived the last sixty-six million years of geologic activity, but paleontologists still comb through fossil beds, searching for the last common ancestor of dogs and cats.
There must have been a hungry little mammal – they were all little back then (Rose) – that either survived the K/T extinction or developed very soon afterwards, during the first epoch of the Age of Mammals – the Paleocene. (Benton and others, page 66; Fox and others; Nyakatura and Bininda-Emonds, 2012)
How do the boffins know that?
From cat and dog teeth, specifically, certain upper and lower cheek teeth that fit together like scissors blades.
They’re called carnassials, after the French word for “carnivorous.”
Carnassials are why Fluffy rarely takes food from your hand. The cat has to use its cheek teeth on food.
Its impressive fangs and incisors are specialized murder tools, as we’ll see in #6 later.
As you can see, cats and dogs aren’t the only ones with carnassials. All members of the biological order Carnivora have them. (Revell)
It’s always the same teeth, too – the last premolar on the upper jaw and the first molar on the lower jaw. (University of California Museum of Paleontology)
This means that all carnivorans inherited their carnassials from the same ancestor.
That’s the K/T-surviving and/or fast-evolving animal paleontologists would love to identify in the geologic record.
Now, the next misconception is something that every zoo visitor and safari adventurer takes for granted. Scientists once thought it was true, too.
9. Hyenas and the big cats are unrelated.
Not surprisingly, wildlife biologists used to classify hyenas as caniforms. (World Heritage Encyclopedia) That’s science-speak for “dog-like.”
Today’s caniforms include (but aren’t limited to) dogs, wolves, foxes, skunks, bears, weasels, badgers, wolverines, raccoons, and . . . walruses?
Yes, and otters and seals, too. Not killer whales, though. (Heske)
Hyenas were moved out of the group when genetic testing showed that they are really feliforms, though it isn’t clear exactly how they fit in with the rest of the “cat-like” carnivorans. (Barycka)
Feliforms include families you don’t usually think of as related to cats until you see them all together. Here are modern representatives of the whole feliform group (Heske):
OK, the hyena still seems strange there, but molecular analyses don’t lie.
By the way, meerkatts are in the mongoose family. They are smart, but cheetahs are smarter.
Since paleontologists are still looking for the last common ancestor of dogs and cats, you probably won’t be surprised to hear that no one knows for sure when these two groups went their separate ways.
The oldest known caniform and feliform fossils go back to the Eocene – the second epoch of the Age of Mammals. However, molecular studies suggest that the big break may have happened long before then. (Benton and others; Nyakatura and Bininda-Emonds, 2012; University of Edinburgh)
The exact date hasn’t been pinned down yet. Some researchers think . . . Uh-oh. Let’s move on – something really horrible has just appeared in the tree branches over your head . . . act casual and don’t turn your back on it.